How many monuments of ancient cultures have perished irrevocably on earth? How many amazing works of art and technical creations of human genius have turned into decay? It is hard to imagine. Another thing is the Ocean. The sea element carefully preserves everything that a person gave to it voluntarily or against his will. Under the cover of silt, sand and coral, the remains of cities and settlements with majestic temples and buildings are reliably hidden, and fragile ships with their contents are stored in Neptune’s hiding places. The book by Doctor of Historical Sciences A. V. Okorokov is about the most interesting and exciting discoveries of underwater archeology. The materials were prepared on the basis of the author’s personal experience and testimonies of expedition participants.